1. Field of the Invention
The present invention relates to refractory ceramics and specifically, to refractory ceramics for use in glass forming and/or delivery systems.
2. Technical Background
The fusion process is one of the basic techniques used to produce sheet glass and can produce sheet glass having surfaces with superior flatness and smoothness relative to sheet glass produced by alternative processes, such as for example, the float and slot drawn processes. As a result, the fusion process has found advantageous use in the production of the glass substrates used in the manufacture of light emitting displays, such as liquid crystal displays (LCDs).
The fusion process, specifically, the overflow downdraw fusion process, includes a glass supply pipe which provides molten glass to a collection trough formed in a refractory body known as an isopipe. During the overflow downdraw fusion process, molten glass passes from the supply pipe to the trough and then overflows the top of the trough on both sides, thus forming two sheets of glass that flow downward and then inward along the outer surfaces of the isopipe.
Surfaces of a glass forming and/or delivery system that are in contact with molten glass are typically comprised of a precious metal, such as platinum. The stability of the glass supply pipe and other components can be dependent upon the materials and techniques of construction. When subjected to operating temperatures of 1,000° C. or more, conventional materials can sag, creep, and/or deform, resulting in system and/or component failure.
There is a need to address the aforementioned problems and other shortcomings associated with glass forming and/or delivery systems and the traditional approaches for producing components for glass forming and/or delivery systems. These needs and other needs are satisfied by the methods and articles of the present invention.